Field of the Invention
The present invention relates to a linear brake apparatus for an escalator and, more particularly, to a low-speed brake apparatus for an escalator in which the step and hand rail of the escalator are linearly braked optimally.
Discussion of the Related Art
As noted, an escalator is installed in buildings having a variety of types of structures. The escalator in which steps are installed on an endless track can move much many people than an elevator to an upper floor or a lower floor. The escalator has an open type structure to enable people thereon to see a view around. The escalator is widely installed on department stores, hotels, large shopping centers, and subway stations.
The structure of such an escalator is described below. A driving motor for generating a motive power for up and down driving steps connected to the endless track onto which a passenger steps and driving sprockets connected to the driving shaft of the driving motor are connected by a driving chain. Step sprockets rotated when the driving shaft is rotated by the motive power of the driving motor moves step chains, so the escalator operates to go up and down.
Such an escalator has a main brake included in the driving motor and is driven by a controller, if necessary. The escalator is suddenly braked when a safety accident, such as a get-between accident, occurs by stopping the rotational movement of the driving motor.
The driving sprockets on both sides of the steps for the step driving of the escalator are connected by the driving shaft. The driving chain inserted into a driving motor rotation shaft rotates the driving sprockets, thereby driving the steps.
Accordingly, when the driving chain connecting the driving motor and the sprockets of the driving shaft and transferring a motive power is broken, although the braking power of the main brake operates, the braking power cannot be transferred to the steps of the escalator. Accordingly, the steps of the escalator are suddenly accelerated while going down due to weight itself and weight of a passenger. The steps of the escalator are stopped while going up, instantly reversed, and accelerated to go down. Accordingly, there is a problem in that a serious injury accident is frequently generated because a passenger loses his or her balance due to inertia upon going up or down and falls down forward.
A representative example of such an escalator includes Korean Patent Application Publication No. 20-0466157 entitled “Disk hydraulic caliper type safety brake control apparatus for emergency stop of escalator for heavy load” (hereinafter referred to as a “cited invention”).
The cited invention relates to the disk hydraulic caliper type safety brake control apparatus for an emergency stop of escalator for a heavy load, as shown in FIG. 1, including step chains on which the steps of the escalator are installed, an escalator rotation shaft 30 equipped with driving sprockets 36 engaged with the respective step chains and adapted to move the step chains up or down while rotating forward or backward by a driving motor 21, a counter rotation detection sensor which senses the rotation direction of the escalator rotation shaft 30, an overspeed detection sensor which senses the rotation speed of the escalator rotation shaft 30, an emergency stop safety brake 40 configured to block the rotation of the escalator rotation shaft 30 by a mechanical force, and a control unit configured to determine whether abnormality occurs in response to signals from the counter rotation detection sensor and the overspeed detection sensor and to control the emergency stop safety brake 40.
The emergency stop safety brake 40 includes a disk brake 41 additionally installed on the escalator rotation shaft 30 and hydraulic calipers 42 configured to limit the rotation of the disk brake 41 by simultaneously applying pressure on both sides of the disk brake 41 and to operate in response to a signal from the control unit.
The emergency stop safety brake 40 is installed in accordance with the central portion of the escalator rotation shaft 30 so that the central portion of the escalator rotation shaft 30 can be braked.
The cited invention has a problem in that a serious safety accident may occur because passengers stepping onto the steps of the escalator fall down due to inertia if the escalator going down at a high speed is rapidly braked by a hydraulic caliper type emergency stop safety brake although the driving chain is broken.